STEMS: monomorphic, prostrate, not readily fragmenting when dry, the branch tips appearing straight when dry, forming dense usually cushion-like mats. RHIZOPHORES: produced throughout. LEAVES: monomorphic, 2.5–4.0 mm long, narrowly lanceolate, green to yellowish green when hydrated, the base more or less decurrent (similar in color to the stem) and more or less symmetrically narrowed, the tip with a straight or somewhat curved white seta 0.2–0.5 mm long (sometimes breaking off with age), the margins entire, denticulate, or short-ciliate. STROBILI: 5–30 mm long, the sporophylls lanceolate to broadly lanceolate, narrowed to an acute tip with a short seta, the margins entire or denticulate. MEGASPORES: finely rugose to rugose-reticulate, orange. NOTES: Rock outcrops, ledges, boulders, cliffs, and rarely on open gravelly slopes, on igneous and volcanic substrates and sandstone: Coconino, Mohave cos. (Fig. 1H); 2400–2550 m (7850–8400 ft); e WA s to e CA, e to MT and AZ. REFERENCES: Yatskievych, G. and M. D. Windham. Vascular Plants of Arizona: Selaginellaceae. CANOTIA 5 (1): 39–48, 2009.